Method for separating waxy and oily materials



1952 J. L. BILES ET AL 2, 7

METHOD FOR SEPARATING WAXY AND OILY MATERIALS I Filed June 9, 1948 s Sheets-Sheet 1 ang. 0., 464 0 0 0 4- 1952 J. BILES ET AL METHODFOR SEPARATING WAXY AND om MATERIALS 3 SheetsS heet 2 Filed June 9, 1948 IPI if 1 INVENTOR. Jay/v 4.. 511.5:

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1952 J. L. BlLES ET AL 2,581,573

METHOD FOR SEPARAT ING WAXY AND OILY MATERIALS Filed June 9, 1948 5 Sheets-Sheet 5 A DSORBANT ,9 HOPPER WAX) CHARGE l EEE HEHTER Patented Jan. 8, i952 METHOD FOR SEPARATING WAXY AND OILY MATERIALS John L. Biles and Harold C. MyersQWoodbury, and Theodor Arthur Pctry and Willard H.

Cowell, Wenonah, N. J., assignors to Socony- Vacuum Oil Company, Incorporated, a corporation of New York Application June 9, 1948, Serial No. 31,948

- 17 Claims. 1

This invention relates to a process for the separation of wax and oily constituents present in a wax bearing hydrocarbon stock and more particularly to a process for deoiling waxy petroleum fractions such as slack wax and the like.

The present process is broadly applicable to the problem of separating wax and/ or petrolatum and the like from hydrocarbon oils in substan .tially oil free form. The present process is particularly directed to the deoiling of crystallizable wax present in high waxy stocks such as in slack wax.

A process commonly employed heretofore for the deoiling of wax is the well known sweating process wherein the slack wax is chilled in pans to cause congealing of the wax after which the mass is slowly heated to effect sweating out of the liquid oil. The eficiency of this process is low as compared with other methods from the standpoint of wax yields. Moreover, the process is conducted batchwise and requires a considerable length of time and delicate temperature control during the heating period.

Another process employed is the solvent deoiling process in which the slack wax is mixed with a suitable solvent such as propane or benzolacetone, for example, and then chilled and filtered.

Still another process currently employed is the emulsion deoiling process in which the slack wax is mixed with a non-viscous non-solvent While in molten state after which it is cooled to congeal the wax. Then the congealed wax is separated from the oil in non-solvent emulsion by means of a basket type centrifuge lined with a filter material. Such processes involve extensive wax recycle to provide satisfactory yields of wax with low oil content.

It has been customary in the prior art to em ploy filter aids such as diatomaceous earth in powdered form to act as an aid in the dewaxing of oils by the filtration of the wax from the liquid oil. In such a process the liquid oil from which most of the wax has been crystallized is withdrawn free of the filter aid and the waxy material. The process has not ben found practicable as a method for deoiling waxes to obtain oil free wax. As a matter of fact the waxy material left behind with the filter aid is generally known as slack wax and contains substantial amounts of oil.

In United States Patent 1,278,023, dated September 3, 1918, there is disclosed a process for dewaxing of oils wherein the waxy oil stock is wholly absorbed by a solid porous material such as fullers earth after which the fullers earth is chilled to effect congealing of the sorbed wax. The fullers earth is then treated with a suitable oil solvent whereby the liquid oil is removed leaving behind the wax within the pores of the adsorbentj. The wax is subsequently separated from the solid adsorbent. This process is unsatisfactory because of the difficulty in obtaining satisfactory wax yields and the difficulty of removing the wax from within the pores of the ad sorbent without use of a second solvent for the wax.

A major object of this invention is the provision of a new, improved and economical process for the separation of wax and liquid oils which overcomes many of the disadvantages of the prior art processes.

A specific object is the provision of a novel continuous process for the deoiling of slack wax by means of porous solid adsorbent materials.

These and other objects of this invention will become apparent from the following description of the invention.

The present invention broadly comprises a process wherein the waxy stock such as slack wax is brought into intimate contact with a suitable particle form solid adsorbent material under temperature conditions at which the wax constituents of the wax bearing oil are congealed and become and remain coated on the outer surface of the adsorbent particles while the noncongealed liquid oil constituents are sorbedinto the pores of the adsorbent. Thereafter the wax is removed from the surface of the adsorbent I that the waxy constituents in the waxy stock are in a congealed or crystallized state either prior to, or substantially immediately after being brought into contact with the solid adsorbent particles or are congealed substantially simultaneously upon being contacted with the adsorbent. Also the waxy constituents should remain congealed at least until the step of removing the wax from the adsorbent commences. It will be readily understood by those skilled in the art that such expressions as congealed wax constituents and non-congealed liquid oil constituents and the like as used in describing and claiming this invention do not necessarily mean 'pure oil-free wax or pure wax-free oil since the in non-congealed state some material which chemically should be classified as 'a wax. I For the purposes of describing and claiming this invention awax which is free of oil shall be taken as meaning one in which the oil content is zero as determined by the A. S. -T. M. method for determining oil contents of waxy stocks, A. S. T. 'M. Test Number D721-43T.

The invention may be more readily understood by reference to the drawings attached hereto in which Figure 1 is a highly diagrammatic elevational view of an apparatus arrangement adapted for conducting this invention. Figures 2 and '3 are elevational views, partially in section, show-' ing modified systems for conducting the method of this invention. All of these drawings are highly diagrammatic in form.

Turning now to Figure 1, there is shown a system adapted for conducting the method of this Adsorbent particles are then passed from amount to cover over the layer of waxy stock with a thin layer of adsorbent. The adsorbent is then pressed into the layer of wax by a large spatula'or other suitable means and the process is then repeated until the pan is filled with a mass of congealed waxy charge mixed with adsorbent particles. The mass is chilled to insure the complete desired precipitation of wax constituents and permitted to stand under these conditions until the oil constituents have been sorbed in the pores of the adsorbent. Thereupon the wax may be separated from the surface of the particles .by removing the particles from the pan I Ill andmechanically agitating them together so as to break off the crystallized wax from the surface of the wax particles. Alternatively, the-wax may be melted from the particles by contacting themwithsteam or hot water followed by separation of the melted wax from the adsorbent particles which still hold the oily constituents in the adsorbent pores. The oily constituents may then be removed from the adsorbent by means of a suitable solvent such as a naphtha fraction. This latter alternative may be conducted in pan IIJI if desired, the liquid being poured from the pan at the proper time. The adsorbent particles are then purged free of solvent by means of steam and then returned to tank i! via pipe I09 for arrangement for conducting the process continuously is shown in Figure 2. In this system a waxy stock such as slack wax is pumped by pump I0 through a heater or heat exchanger I I wherein it is heated to a temperature slightly above that at which the waxy constituents begin to congeal. The heated slack Wax then passes via pipe I 3 into the upper section of the elongated vertical vessel I4. A column of the molten slack wax is maintained within section A of the coating tower I4. A column of water or other suit able cooling liquid is maintained within a lower section of tower '14. This liquid should be of greater density than the slack wax and a nonsolvent as to both wax and oil. The water in that portion of the tower I4 just below the slack wax column is maintained at a temperature suffiCiently high to avoid congealing of wax at the interface between the slack wax and water col- This is accomplished by circulating water through pipe I! into and through heat exchanger I8 and back into the water column via pipe I9 just below the interface. Cold water enters the water column via pipe 20 below the level of warm water outlet pipe I]. Particle form porous adsorbent material which may preferably be of spherical form enters the tower M via pipe 2i at about the same temperature as the slack wax or at a somewhat lower temperature. In general, the inlet temperature of the adsorbent should usually be below about 100 F. and preferably below about F. The rate of intro- .duction of adsorbent-is controlled by adjustment of the height of the outlet end of pipe 2| from conical spreader 2,2 and by rotation of spreader 22. The spreader is rotated by means of gears 23, shaft 24 and motor 40. Upright conical baffies 25 and 25 are supported by rods 21 and '28 properly positioned below the spreader 22in such a manner as to distribute the particles of adsorbent uniformly over the entire cross section of the tower I4. The adsorbent particles drop downwardly through the column of slack wax and become coated on their surface with a film of slack wax. The particles then drop into the water column and the cool water acts to congeal the wax constituents on the surface of the particles. When the difference between the particle density and cooling liquid is small it is desirable to add 7 some substance such as pO assium oleate to the water or other cooling .liquid to lower the interfacial tension at the water-slack-wax interface. This will prevent hold up of adsorbent particles at this interface. The particles of adsorbent bearing the congealed material are washed by the water from th bottom of tower I 4 through the curved pipe 29 onto a moving screen belt drainer I 30. The pipe '29 is provided with a vent 3| to break the siphon effect, and the level of the high-.- est point along pipe 29 is such as tomaintain the surface of the wax column substantially constant as indicated in the drawing, the water introduced into tower I4 via pipe 20 being equal in volume to that passing from the tower through pipe 39..

The screen 30 is of a continuous belt type, moving over rollers 32 and 33, one of which is driven by motor 34. The screen is encased in suitable housing 55. A pan 35 positioned under the screencatches the water which is withdrawn via pipe 36 to accumulator 6|. The water is passed from accumulator BI via pipe 62, pump 63 and pipe '20 back to the tower I4. Make up cooling water is added to the accumulator 6i via pipe 54. The adsorbent particles bearing the congealed waxy material are retained by the screen and discharged into conveyor 31. The adsorbent is discharged from the conveyor into one of the sorption tanks 38 and 38, these tanks being several in number although only two are shown and being employed in cycle. When one of the tanks 38 is filled the adsorbent is permitted to stand therein while the temperature is controlled by means of heat transfer tubes (not shown) at a level at which the wax constituents of the slack wax will remain congealed. A suitable cooling fluid may be supplied to the heat transfer tubes within each of the tanks 38 via pipe 4| and withdrawn via pipe 42. The adsorbent is retained within the tank 38 or 38 until substantially all of the non-congealed liquid oil constituents of the slack wax are sorbed from the congealed mass on the surface of the particles into the pores of the particles leaving substantially only the waxy constituents coated on the outer surface of the adsorbent particles. The adsorbent is then withdrawn through outlets 39 and 39 and conveyed by screw conveyors 43 and 44 into the upper section of the wax melting tower 45 which is maintained substantially filled with a column of hot water. The adsorbent particles drop through the column of hot water in a zig zag path provided by baffles 46 so that the wax deposited on the surface of the particles is melted oil from the particles and is passed from the upper section of tower 45 via pipe 48 to the wax separator 49. The molten wax is withdrawn from the upper section of separator 49 via pipe 59 and the separated water is returned via pipe I09, pump and pipe 52 to the lower section of the wax melting tower 45. The water is maintained substantially above the melting point of the Wax by means of the heating coil 53within separator 49. The adsorbent particles which still retain the liquid oil within the pores of the particles are carried from the bottom of tower 45 in a water stream via conduit 54 and discharged onto the moving belt screen drainer 69 which is similar to the screen 30 described hereinabove. The highest level of conduit 54 is such as to permit maintaining tower 45 substantially filled with liquid. ihe hot water passing through the screen 65 is collected in pan 81 and returned via pipe 68 and pump 69 to the separator 49. Hot water make up is added to the system via pipe 10. The filtered adsorbent material passes from the end of moving screen 66 via duct 1| into one of several oil removal tanks 72 and 12 (only two being shown). These tanks are used in cycle, the empty tank being opened to the duct H. When one of the tanks it has become filled to the desired level with adsorbent, it is closed oil from duct H, as by stopping the rotation of the star valve 14 and Y4, and a suitable oil solvent is introduced via conduit or 15' into the tank 12 or 12 and passed through the adsorbent mass until all the sorbed oil is removed. The solvent bearing removed oil is withdrawn from tank 12 via pipe '56 and the oil and solvent may then be separated in suitable equipment which is conventional in the art for that purpose. The solvent employed may be a heated naphtha fraction, benzol, hexane, butyl alcohols, ethyl carbonate and acetone or other suitable oil solvents. After removal of the oil, the adsorbent is drained and then purged free of solvent by means of steam, flue gas or other suitable purge fluid entering via pipe 19.

The purge fluid is withdrawn from tank 12 via pipe 16. The reclaimed adsorbent is then discharged from tank via pipe 89 and may be reused in the deoiling process.

After long periods of continued reuse a deposit of carbonaceous material may accumulate on the adsorbent which is not removed in the reclaiming steps. Inasmuch as this material may eventually plug up the pores of the adsorbent and decrease its efiiciency in the present process, the carbonaceous contaminant should be periodically removed from the adsorbent either by means of suitable solvents or by means of burning with air at elevated temperatures in a manner well known to those skilled in the art.

It will be readily understood that this invention is not limited to the particular details of apparatus arrangement or process step technique shown in Figures 1 and 2. For example, a number of methods may be employed for accomplishing the initial coating of the surface of the adsorbent with the waxy stock. An alternative method is shown in Figure 3 in which is shown an apparatus arrangement which may be substituted for the coating tower M in the system of Figure 2. In Figure 3, there is shown a confined elongated chamber which may be supplied with cold water through pipe 88 so as to maintain a column 88 of cold water therein. The water is continuously withdrawn from the upper section of vessel 85 via pipe 81 so as to permit continuous circulation of the water through column 88. An adsorbent supply hopper 89 supplied with adsorbent via pipe 98 is positioned above chamber 85. A feed pipe 94 extends vertically downward from hopper 99 into chamber 85 and terminates a substantial distance below the surface level of the water column in chamber 85 but preferably within the upper section of the water column. A slack wax supply hopper 92 is also positioned above the chamber 85, and a pipe 93 extends downwardly from hopper 92 to connect into feed pipe 94 a short distance above the surface level of the water column 88. Slack wax is heated in heater H0 and supplied to hopper 92 in molten condition. It then flows via pipe 93 into pipe 94 where it mixes with adsorbent from hopper 89 at a temperature only slightly above the congealing temperature of the wax constituents of the slack wax charge. The liquid charge stock fills in the void spaces between the stream of solid particles flowing in pipe 94 and solidifies as the stream reaches the column of cool water 88. If desired, the congealing of the wax may be aided by supplying the adsorbent from hopper 99 at a temperature somewhat below that required to congeal the wax constituents of the molten slack wax charge. Due to the head of adsorbent in pipe 94 above the solidified mass near its outlet, a rod or ribbon of adsorbent encased in solidified waxy charge stock is extruded from the lower end of pipe 94 into the water column. The extrusion may be aided, if desired, by a mechanically agitated rod or other suitable device III within the pipe 94 which may be operated from an external location above the hopper 89. If desired the temperature of the waxy stock may be so regulated in hopper 92 as to cause the waxy constituents to be partially crystallized as they flow through pipe 93 or as to provide for crystallization of the waxy constituents substantially simultaneously upon initial contact with the adsorbent in pipe 94. The rod or ribbon of extruded material drops through the column of cooling water 88 and becomes further cooled so as to complete the congealing of the waxy constituents throughout the cross section of the ribbon. The extruded ribbon may be caused to break up to some extent into chunks of solidified charging stock encasing adsorbent particles as it falls throughthe water column 88 and the material is removed from the lower section of the chamber 85 by means of the continuous bucket conveyor 99 which connects into chamber 85. The buckets I of this conveyor may be perforated so as to permit draining of liquid from the mass of adsorbent particles encased in congealed waxy stock once the buckets rise above the surface level of column 88. If desired, adsorbent may be further drained free of Water by delivery from conveyor 99 into the drainer 55 shown in Figure 2. In many operations adequate draining may be accomplished as the material is elevated in conveyor 99 and the adsorbent material may be conveyed directly to the adsorption tanks 38 and 38 shown in Figure 2.

When the method described in Figure 3 is employed the pipe 94. should preferably be subdivided near its lower end by means of vertical partitions so as to form a number of vertical passages having a maximum horizontal average diameter of about one half inch in diameter. The diameter of the ribbons is thereby limited to a size Which will permit rapid transfer of heat into the center of the ribbons so as to accomplish quick congealing of the Wax throughout the ribbon cross section. In general, the pipe 96 should extend about 0.5 to lOinches below the surface of water column 838 depending on the water temperature, and being less the lower the water temperature and higher the congealing temperature of the waxy constituents. The waxy stock should enter the pipe 94 about 0.5 to 24 inches above the surface of water column 86.

It will be readily understood that apparatus and methods other than that shown in Figure 2 may be employed to accomplish the transfer of materials between vessels, the adsorption step and the draining and wax melting and oil recovery steps. Moreover, the removal of wax from the surface of the adsorbent particles may be accomplished by methods other than by the melting ofthe wax. For example, the Wax may be removed from the particles while in solid formby mechanical attrition. This latter method is particularly applicable when the wax is of brittle texture and where the adsorbent particles are spherical in form. One method for accomplishing the mechanical separation is to rotate the adsorbent particles in a closed drum for a perio-d'of time to crack off the brittle wax. The

particles of Wax may then be separated from,

the adsorbent particles by elutriation, i. e. suspension in a stream of gas the flow rate of which is controlled to carry off the Wax particles without entraining the adsorbent.

The step of removing the oil from the pores of the adsorbent particles may be accomplished by methods other than those employing oil solvents. For example, the adsorbent may be heated and steamed to remove the oil.

A wide variety of porous adsorbent materials stituents of the waxy charge stock. The ad-- sorbent particlesshould be of substantial size, as distinguished from powderedadsorbents. When powdered adsorbents of size less than about 100 mesh Tyler are employed the waxy constituents tend to be sorbed into the pores along with the oily material before. complete congealing of. the waxy constituents can be. accomplished thereby preventing the desired separation. In general. it has been found that the adsorbent particles should be broadly at least about 0.01 inch average diameter and preferably at least about 0.022 inch and less than about 0.5 inch average diameter. A preferred adsorbent is a synthetic si1icaalumina gel catalyst in spherical form prepared in the manner described in United States. Patent 2,384,946 issued September 18, 1945, to'Milton M. Marisic.

The operation should be conducted so as to effect congealing of the waxy constituents immediately on contact or as soon as possible after the initial contacting with the adsorbent.

The ratio of adsorbent to waxy charge stock employed in the process of this invention will depend to some extent upon the oil sorption capacity of the, adsorbent, the. percentage of. oil present in the waxy stock and other operating variables. In general, for synthetic gel catalysts the ratio should be of the order of 0.5 to pounds of adsorbent per pound of waxystock. In any case, sufiicient adsorbent should be em: ployed to sorb substantially all of thev oily constituents in the waxy charge.

The length of time to be devoted to. the sorption period during which non-congealed liquid constituents are sorbed into the pores of the adsorbent will vary depending upon the thickness of the waxy stock coating on the adsorbent particles and upon the particular adsorbent involved and the viscosity and molecular size of the. oily constituents under the sorption temperature conditions required to maintain the waxy constituents in a congealed state. In general, it has been, found that, with adsorbent particles of about 0.09 to 0.19 inch diameter and having a porosity similar to a synthetic silica-alumina gel catalyst, the length of the sorption period should be at least about 0.1 hour and should preferably be of the order of about 1 to 24 hours.

In general, the average thickness of the waxy stock "coating around each adsorbent particle should be less than about 0.1 inch and preferably less than about 0.05 inch.

As an example of the. process of this invention the deoiling of a waxy stock by the general method shown in Figure 2 may be considered. The waxy charge stock was a parafiinic petroleum stock having a melting point of 116.9 F. as determined by the test procedure recommended by the American Society for Testing Materials, Test Number A. S. T. M. D87-42 and an oil content of 19.2 as determined by A. S'. T. M. tentative Test Number D-721-43T. The adsorbent employed umn of molten waxy stock one inch in depth and maintained at about 126 to 133 F; The weight ratio of catalyst to waxy stock charge was about 3.5 to 1. The catalyst beads bearing a coating of waxy stock then dropped through a column of cooling water maintained at about 70 F. About 0.3-0.5% potassium oleate was added to the water to reduce the interfacial tension at the water wax interface. The catalyst bearing the congealed coating of waxy stock was permitted to stand about 4 hours at about 80 F. after which the wax was removed by attrition from the surface of the particles. The recovered wax had a melting point of 125.3" F. and an oil content of 3.2% by weight and the yield of recovered wax amounted to 58% by weight based on the waxy stock charge or 72% by weight of the wax present in the charge as determined by .A. S. T. M. Test Method D-721-43T. By way of comparison the yield of wax obtained by the method described above using a minimum cooling water temperature of 70 F. amounted to 83% by weight of the yield of wax obtained by solvent deoiling the same waxy stock employing benzol-methyl ethyl ketone as the solventat a temperature of zero degrees F. The wax obtained by the solvent deoiling process contained 2.4% by weight oil.

In another experiment employing the same conditions outlined above except that the sorption period was increased from 4 to 20 hours a final wax product containing only 1.4% oil was obtained but the wax yield based on the charge was somewhat lower.

In still another experiment conducted similarly to the one first described the sorption period was increased from 4 to 20 hours and the absorbent to oil charge ratio was decreased from 3.5 to about 1.4. The wax yield was increased to 61% by Weight of the original waxy charge but the oil content in the recovered wax increased to about 6.7% of the wax.

In another experiment conducted according to the method described in connection with Figure 3, a waxy charge stock having a melting point of 113.5 F. and an oil content of 20.3% oil by weight was deoiled employing the same adsorbent. Referring to Figure 3, the adsorbent feed pipe 94 measured one half inch internal diameter and molten charge entered the pipe 94 about one inch above the surface of water column 88. The one half inch rod extruded from pipe 94 dropped into a cold water bath maintained at about 70 F. The adsorbent to waxy charge stock weight ratio was about 1.8 to 1.0. The extruded material was permitted to stand at 80 F. for 3 hours after which the wax was removed by attrition in a ball mill. The wax yield amounted to 68% of the wax present in the charge stock as determined by A. S. T. M. tentative Test Number D-721-43T and the wax product contained 4.3% oil and had a melting point of 123.3 F.

In an experiment conducted on the same charge stock and with the same type of adsorbent by the batchwise method described in connection with Figure l and employing an adsorbent to waxy charge ratio of 2.0 to 1.0 and a sorption period of 66 hours at 80 F. the yield of wax containing 4.6% oil was about 60% of that in the waxy charge.

In this latter experiment the waxy stock was cooled in pan Hi! to about 70 F. to accomplish crystallization of the waxy constituents before the adsorbent was added. The wax remaining on the surface of the adsorbent particles after the sorption period was removed by mechanical attrition.

It should be understood that the specific details of operation and of apparatus arrangement and the specific modifications of this invention given hereinabove are intended as exemplary and the invention is not to be construed as being limited thereto or otherwise limited except as limited by the following claims.

We claim:

1. The method for separating wax and oily constituents present in a wax bearing mineral oil which comprises: subjecting the wax bearing oil to an intimate contacting with a particle form solid adsorbent material composed of particles of average diameter within therange 0.022-0.5inch, maintaining the wax to be separated in congealed state by control of the temperature beginning at a time falling within the period. of any time prior to the contacting to substantially immediately after initial contacting of the wax bearing oil with the adsorbent and throughout at least most of said contacting at a level at which wax constituents of said wax bearing oil are congealed whereby the congealed wax constituents remain deposited on the surface of said adsorbent andthe non-congealed liquid constituents are sorbed into the pores of said adsorbent, and thereafter removing said wax constituents from the surface of said adsorbent while leaving said liquid constituents within the pores of said adsorbent.

2. The method for removing oily constituents from a waxy hydrocarbon stock which comprises:

subjecting said waxy stock to an intimate contacting with a particle form solid adsorbent ma-. terial of at least 0.01 inch average particle diameter, maintainin the temperature of the waxy stock during at least most of said contacting at a level at which waxy constituents of said stock are precipitated and beginning at a time falling within the period of any time prior to the initial contacting to not more than ten minutes after the initial contacting, whereby the non-precipitated liquid constituents are sorbed into the pores of said adsorbent while the precipitated waxy constituents remain deposited on the outer surface of the adsorbent particles, thereafter effecting removal of said precipitated waxy constituents from said adsorbent separately of said sorbed oily constituents and finally effecting removal of said non-precipitated, sorbed liquid constituents from said adsorbent.

3. The method for removing oily constituents from a waxy hydrocarbon stock which comprises: subjecting said waxy stock to an intimate contacting with a particle form solid adsorbent material in which the average particle diameter is at least 0.01 inch, maintaining said waxy stock in contact with said adsorbent for a period of at least about 0.1 hour, chilling the waxy stock to effect congea-ling of at least most'of the waxy constituents therein beginning within the period of any time prior to'the contacting to substantially immediately .after initial contact of the waxy stock with the adsorbent and maintaining said waxy stock chilled during the contacting, whereby the non-congealed liquid constituents of said waxy stock are sorbed into the pores of said adsorbent particles while the congealed waxy constituents are left deposited upon the surface of said adsorbent particles, effecting removal of the congealed waxy constituents from said adsorbent particles in a separate zone while leaving substantially all of said liquid constituents still sorbed in the particle pores and finally separately removing the sorbed liquid constituents from said adsorbent.

4. The method for separating wax and oily constituents present in a waxy mineral oil stock 11 which comprises: intimately contacting the wax bearing oil with a particle form solid adsorbent material in which the average particle diameter is at least 0.01 inch, substantially excluding the sorption of the waxy constituents in said mineral oil stock into the pores of said adsorbent particles by maintaining said waxy constituents in congealed form while permitting the non-congealed liquid constituents to be sorbed into the pores of said adsorbent, and after substantially all of said liquid constituents are sorbed in the pores of said adsorbent effecting a separation of the adsorbent bearing said liquid constituents from said waxy constituents in a separate zone.

5. The method of separating oily constituents from waxy constituents present in a waxy hydrocarbon stock which comprises: cooling said waxy stock to effect at least partial crystallization of the Waxy constituents and then coating the waxy stock onto the surface of particles of. solid adsorbent material of greater than about 0.01 inch average diameter, permitting the adsorbent particles to remain coated with said waxy stock for a period within the range 011 to 24 hours and maintaining the temperature of the waxy stock during substantially said entire period at a level at which waxy constituents in said stock are congealed whereby the non-congealed liquid constituents are sorbed into the pores of said adsorbent particles while the congealed waxy constituents remain on the surface of said particles, thereafter effecting removal of said'waxy con-- stituents from the surface of said adsorbent particles while leaving sorbed said non-congealed liquid constituents.

6. The method for removing oily constituents from a waxy hydrocarbon stock which comprises: subjecting said waxy stock to an intimate contacting with a particle form solid adsorbent material having an average particle diameter of at least 0.01 inch, effecting sorption of the liquid oily constituents of said waxy stock into the pores of said adsorbent particles while substantially preventing sorption of the wax constituents by maintaining the temperature during substantially the entire contacting at a level at which thewax constituents are congealed, and thereafter melting the congealed wax constituents from the surface of said adsorbent particles while leaving the oily constituents sorbed in the pores of said particles collecting the melted wax separately from the adsorbent particles and sorbed oily constituents.

7. The method for removing oily constituents from a waxy hydrocarbon stock which comprises: effecting substantial congealing of the waxy con stituents in the waxy stock, thereafter subjecting said waxy stock to an intimate contacting with a particle form solid adsorbent material composed 'of' particles of'at least 0.01 inch average diameter under conditions of temperature wherein the waxy constituents of said stock remain congeal :l, continuing said contacting until substanti'allyall of the non-congealed liquid constituents of said stock are sorbed into the pores of said adsorbent particles while leaving the congealed wax on the surface of said particles, thereafter heating said adsorbent particles to meltthe congealed wax constituents from the surface thereof, collecting the melted wax, separately treating the adsorbent freed of wax with a suitable solvent to remove the sorbed oil therefrom, effecting removal of the solvent from the adsorbent andreusing said adsorbent for contacting waxy stocks as aforesaid.

8. A method for deoiling waxy petroleum fractions which comprises: chilling the waxy fraction T2 in a suitable container to effect at least partial conge'aling of the'waxy constituents, wherebya congealedsemi-solid'mass is formed, mixing particles of a suitable porous adsorbent material of at least 0.01 inch average particle diameter with said congealed mass and permitting the particles to remain mixed in said mass until substantially all of the non-congealed oily constituents are sorbed into the pores of said adsorbent particles, then removing the waxy constituents from the surface of said particles in a separate zone While leaving the liquid oily constituents sorbed in the pores of said particles, finally separately removing the oily constituents from the pores of said particles and reusing said particles to deoil additional slack wax as aforesaid.

9. A method for deoiling waxy petroleum fractions which comprises: chilling the waxy fraction in a suitable container to "effect at least partial congealing of. the waxy constituents, whereby a congealed semi-solid mass is formed, pressing particles of a suitable porous adsorbent material into said congealed mass, said particles being of at leastrabout 0.01 inch average diameter, permitting the adsorbent particles to remain in said semisolid mass while maintaining the waxy constituents congealed for a period of at least about 0.1

, hydrocarbonstock which comprises: coating said waxy stock onto thesurface of particles of solid adsorbent material of greater than about 0.01 inch average diameter, permitting the adsorbent particles to remain coated with said waxy stock for a period of at least about 0.1 hour and maintaining the temperature of the waxy stock during substantially said entire period at a level at which waxy constituents in said stock are congealed whereby the non-congealed liquid constituents are sorbed into the pores of said adsorbent particles while the congealed waxy constituents remain 'on the surface of said particles, thereafter dropping the particles of adsorbent through a bath of water heated to a temperature sufficiently high to melt said waxy constituents off of said particles, separating the water and molten waxy constituents from the adsorbent particles, and separating the waxy constituents from said heated water in a separate stituents of said waxy stock into the pores of oil with the waxy constituents initially infliquid phase to an intimate contacting with a particle form solid adsorbent material comprising particles of at least 0.01 inch diameter, thereupon quickly cooling the mixture and maintaining the tem perature during most of said contacting at a level at which wax constituents of said wax bearing oil are congealed whereby the congealed wax constituents remain deposited on the surface of said absorbent and the non-congealed liquid constituents are sorbed into the pores of said adsorb ant, and thereafter removing said waxing constituents from the surface of said adsorbent while leaving said liquid constituents within the pores of said adsorbent.

13. The method for removing oily constituents from a waxy hydrocarbon stock which comprises: cooling the waxy stock to a temperature only slightly above that at which the waxy constituents are congealed and then subjecting said waxy stock initially in liquid form to an intimate contacting with a particle form solid adsorbent material of at least 0.01 inch average particle diameter, lowering the temperature of said waxy stock shortly after the initial contacting and maintaining the temperature thereof during at least most of said contacting at a level at which waxy constituents of said stock are precipitated whereby the non-precipitated liquid constituents are sorbed into the pores of said adsorbent while the precipitated waxy constituents remain deposited on the outer surface of the adsorbent particles, thereafter efiecting removal of said precipitated waxy constituents from said adsorbent separately of said sorbed oily constituents and finally eifecting removal of said non-precipitated, sorbed liquid constituents from said adsorbent.

14. The method of separating oily constituents from waxy constituents present in a waxy hydrocarbon stock which comprises: coating said waxy stock as a liquid onto the surface of particles of solid adsorbent material of greater than about 0.01 inch average diameter, substantially immediately chilling the coated adsorbent to efiect congealing of wax constituents in said waxy stock coated on said adsorbent particles, permitting the adsorbent particles to remain coated with said waxy stock while maintaining said wax constituents in congealed form until substantially all of the non-congealed liquid constituents of said waxy stock are sorbed into the pores of said particles leaving the congealed waxy constituents on the surface of said particles, thereafter physically removing said wax constituents from the surface of said adsorbent particles still in congealed form.

15. The method of separating oily constituents from waxy constituents present in a waxy hydrocarbon stock which comprises: coating said waxy stock onto the surface of particles of an inorganic oxide gel adsorbent consisting of par-- ticles of generally spheroidal shape and of an average diameter of at least about 0.01 inch, permitting the adsorbent particles to remain coated with said waxy stock for a period within the range 0.1 to 24 hours and maintaining the temperature of the waxy stock during substantially said entire period beginning at least substantially immediately after initial contact with said adsorbent at a level at which waxy constituents in said stock are congealed whereby the noncongealed liquid constituents are sorbed into the pores of said adsorbent particles while the con- 16. The method of deoiling slack wax stocks which comprises: coating said slack wax stock in liquid form onto the surface of particles of adsorbent material in an adsorbent coating zone, said adsorbent particles being of at least 0.01 inch average diameter, chilling the coated adsorbent particles to eifect precipitation of wax. constituents in said slack wax stock coated thereon at least within about 10 minutes of the beginning of the adsorbent coating, maintaining the wax constituents in precipitated form on said absorbent particles for a period of at least 0.1 hour until substantially all of the non-precipitated liquid constituents of said slack wax are sorbed into the pores of said adsorbent particles leaving the precipitated wax on the surface of said particles, effecting removal of the precipitated wax from the surface of said adsorbent particles while leaving the liquid constituents still sorbed in the pores of said adsorbent particles, separately effecting removal of the sorbed liquid constituents from the adsorbent particles and reusing said adsorbent particles in said coating zone as aforesaid.

17. A method for separating oily constituents from waxy constituents present in a waxy hydrocarbon stock which comprises: mixing particles of a suitable solid adsorbent of at least 0.01 inch average diameter with said waxy stock while it is in liquid form and then quickly cooling the mixture to effect crystallization of the waxy constituents of said stock, whereby the adsorbent particles become coated with a layer of waxy stock in which the waxy constituents are crystallized, permitting the adsorbent particles to remain coated with said waxy stock until substantially all the oily constituents are sorbed into the pores of the adsorbent particles leaving the crystallized waxy constituents on the surface of the particles, thereafter effecting removal of said waxy constituents from the surface of said adsorbent particles while leaving the non-congealed liquid oily constituents still sorbed in the pores of the adsorbent particles and separately removing the sorbed oily constituents from said adsorbent particles.

JOHN L. BILES.

HAROLD C. MYERS. THEODOR ARTHUR PETRY. WILLARD H. COWELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,278,023 Rosenbaum Sept. 3, 19 18 1,509,325 Wier et al Sept. 23, 1924 1,509,326 Wier Sept. 23, 1924 1,714,133 Phillips et al. May 21, 1929 1,831,433 Zoul Nov. 10, 1931 2,398,101 Lipkin Apr. 9, 1946 OTHER. REFERENCES (Allibone) Journal of the Institute of Petraleum, vol. 27, pages 94-408 (1941). 

